We measured a native crystal of the heat shock protein hsc20, aimed at obtaining low resolution diffraction data for initial phase determination using the ab initio phasing technique, developed by S. Subbiah. The data have been processed successfully and we obtained 100% completeness from 100 to 15 E resolution range with a high completeness down to 12 E, with an overall R factor of 7.0%. The ab initio phasing calculation is now in progress.